Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1v1377-0041qe-HB for pgsql-performance@arkaria.postgresql.org; Tue, 23 Sep 2025 13:31:25 +0000 Received: from localhost ([127.0.0.1] helo=malur.postgresql.org) by malur.postgresql.org with esmtp (Exim 4.94.2) (envelope-from ) id 1v1375-005dis-6h for pgsql-performance@arkaria.postgresql.org; Tue, 23 Sep 2025 13:31:23 +0000 Received: from makus.postgresql.org ([2001:4800:3e1:1::229]) by malur.postgresql.org with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1v1374-005dij-Sy for pgsql-performance@lists.postgresql.org; Tue, 23 Sep 2025 13:31:22 +0000 Received: from mail1.dalibo.net ([51.159.93.128] helo=mail.dalibo.com) by makus.postgresql.org with smtp (Exim 4.96) (envelope-from ) id 1v1372-001wag-21 for pgsql-performance@lists.postgresql.org; Tue, 23 Sep 2025 13:31:21 +0000 Received: from [192.168.1.11] (5-49-10-71.hfc.dyn.abo.bbox.fr [5.49.10.71]) by mail.dalibo.com (Postfix) with ESMTPSA id 2EE0824D4A; Tue, 23 Sep 2025 15:31:19 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=dalibo.com; s=a; t=1758634279; bh=ZZKs9yL647SkJ6TtJI+mx0gZjSm7JEsTUhekkYMeW3o=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=M89C/ebEA5eVnFsCNBKQ6iAnOdR594SrUemKBTbG6eu1CHOMMUj5tqtGK+wjmOrTx FtAZ2vbU4yq3SP/FG3zv679EwLFcXXh49duUHxGdgXNBpDvpaq51qF5DCPTRMzgRDr U8xAKQOGbeHIvvfsmZ+/F2joDbcMx3fFqStpr2zI= Message-ID: Date: Tue, 23 Sep 2025 15:31:18 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Indexes on expressions with multiple columns and operators To: Andrei Lepikhov , Tom Lane Cc: "pgsql-performance@lists.postgresql.org" , Jehan-Guillaume de Rorthais , Christophe Courtois , Laurenz Albe References: <1507576.1758120083@sss.pgh.pa.us> <62133334-b844-4d0b-b248-1a8446757e5f@dalibo.com> <1916727.1758209549@sss.pgh.pa.us> <1972974.1758213639@sss.pgh.pa.us> <76fbd9ef-1fbb-49f0-bc8b-844462b18d1d@dalibo.com> <2432873.1758387110@sss.pgh.pa.us> <6ad08c0c-2c03-4b30-b5a7-dc486aa29c52@dalibo.com> <493a013c-63d1-467a-b9ec-352f77baf37a@dalibo.com> <9756a3e9-5dea-4506-a077-72a4d9c302df@gmail.com> From: =?UTF-8?Q?Fr=C3=A9d=C3=A9ric_Yhuel?= Content-Language: fr, en-US Autocrypt: addr=frederic.yhuel@dalibo.com; keydata= xjMEXn3bgxYJKwYBBAHaRw8BAQdA6tX5FT/n5ztMWIoBdl6k5avvu65fv6ryfVzIx/aH3V3N JEYuIFlodWVsIDxmcmVkZXJpYy55aHVlbEBkYWxpYm8uY29tPsKWBBMWCAA+FiEEi7OTyf6H ePS+C6n11XGWhN8zGNUFAmZDVJ8CGwMFCQtfi90FCwkIBwIGFQoJCAsCBBYCAwECHgECF4AA CgkQ1XGWhN8zGNV65gEA6o+UrebFjn2CIAOYwP3CiiJugiM5TMH9yJyehQua5ZoA/2ChxiVn 8OUaAw/ErxJmQi1mSN0tNZBL/KhkUPBDUDQNzjgEXn3bgxIKKwYBBAGXVQEFAQEHQCuh5cLQ AtEBXHa2Fmtp0kduBu7msM7qO/gaEcdjFUdiAwEIB8J+BBgWCAAmAhsMFiEEi7OTyf6HePS+ C6n11XGWhN8zGNUFAmZDVJ8FCQtfi90ACgkQ1XGWhN8zGNWOOAEArSqePBqfd4Kx4ulACaWO 6fM+XSDfUlBAQXx9rU6DR4MBALwozl9g91tRysim6lKxggvBfp/PvbpTZNrxYLWB2fYP In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit List-Id: List-Help: List-Subscribe: List-Post: List-Owner: List-Archive: Archived-At: Precedence: bulk On 9/23/25 12:43, Andrei Lepikhov wrote: > But is it the same for the 'distinct' statistics? It seems you should > love it - the number of groups in GROUP-BY, DISTINCT, and even HashJoin > should be estimated more precisely, no? I think it has more potential, and I would love to use this weapon, but I haven't had the opportunity yet. It would be interesting to know how much it is used in real life. To get back to the topic of partitioned statistics, do you know if SQL Server is smart enough to handle this case [1] that we discussed last year? (with filtered statistics) [1] https://www.postgresql.org/message-id/flat/b860c71a-7cab-4d88-ad87-8c1f2eea9ae8%40dalibo.com